Connecting Pods/Nodes together on a grid using pathfinding?

Hello, I'm currently working on a Random Level Generation mode for my game, in which I spawn a number of rooms of a uniform size, randomly on a grid. I then would like to connect all of the rooms together to form a cohesive level that the player can explore, though I don't really know how to do this. Attached is an example of what the level would initially spawn. I would like to have each room be connected so that none are inaccessible. What is the best way of doing this?